Overloud-MoReVoX REmatrix

Figure 1: REmatrix can mix five convolution reverbs with five other effects and EQ. The Master effects (GUI top-center) and a room IR’s Extended Controls panel (left side) are shown here.

REmatrix is the space-y brainchild of joint developers Overloud and MoReVoX. Supplied as both a plug-in and stand-alone application, REmatrix combines five different convolution reverbs that you can further process with EQ and five effects. Scores of impulse responses are included with the software, and you can import your own (in WAV and AIFF formats). I reviewed Version 1.0.10 of the AU plug-in in Digital Performer V. 8.06, using an 8-core Mac Pro running OS X 10.9.5.

At the bottom of its GUI, REmatrix provides five mixer channel-like slots; you can load a single impulse response into each (see Fig. 1). Each slot is dedicated to recalling one particular type of IR—hall, room, plate, early (reflections), or special (effects)—from an associated browser. Each slot provides a fader for adjusting the IR’s level, plus associated L/R ladder-style meters with clipping indicators. (REmatrix affords both stereo and mono-to-stereo operation.) You can adjust all five IRs’ levels together by holding the Shift key down while adjusting any one fader, thereby preserving the combined reverbs’ relative balance. Each IR also has its own solo and mute buttons.

Toggling a button below an IR’s fader alternately opens a global presets browser and the IR’s Extended Controls panel on the left side of the GUI. Presets store and recall the entire state of the plug-in and are arranged in banks named for their suggested applications: voices, drums, keyboards and so on. The Extended Controls panel hosts a browser used to load a single IR—whether supplied by the factory or imported from your own library—into a slot. There you can also edit the currently loaded IR as follows: Adjust the length of its reverb tail, apply 2-band parametric EQ, pan its stereo positioning, and adjust its stereo width (from mono to wider than normal) and pre-delay time. At extreme settings, the parametric equalizer’s Q controls provide shelving, and highpass and lowpass filtering.

The top-center section of the GUI is the Display area. Toggling the Master button in this section alternately shows a waveform view or a Master view, in which a block diagram appears. The diagram shows how the plug-in’s combined IRs and built-in effects are connected in the signal path (see Fig. 1). The impulse responses can be processed—together as a group, not individually—by modulation, delay, algorithmic reverb, drive, compression and EQ. Clicking once on the icon for a processor in the block diagram gives you access to the processor’s parameter controls for adjustment, whereas double-clicking alternately activates and bypasses the processor.

Toggle the Master button so it’s not highlighted, and the block diagram is replaced by a waveform view for whichever IR you select. In this view, a slider lets you proportionally adjust the reverb time for all the reverbs as a group: from half to double their original lengths. In both the waveform and Master views, separate meters show L/R input and output levels for the plug-in and include temporary-hold clipping indicators.

Master View’s Effects

The configuration of the signal chain for REmatrix’s effects blocks is fixed and can’t be altered. All IRs that are active in the current preset are summed and then sent first to a modulation effect, which at extreme settings can produce chorusing. The modulator feeds an HPF and algorithmic reverb, in that order, in a parallel circuit; controls allow you to adjust the length of the algorithmic reverb’s tail, the geometry of its virtual space, and its timbre and output level. In a second parallel path fed by the modulator, a stereo delay can be set to different times in left and right channels, filtered with an HPF and LPF, and regenerated (fed back on itself). Unfortunately, only the left channel’s delay time can be synched to the host’s tempo; you must manually set the right channel’s delay time by applying to it an offset (in milliseconds) to the left channel’s delay time. Both the stereo delay and algorithmic reverb are disabled when an IR is soloed, a good thing.

The modulator, algorithmic reverb and delay’s outputs are summed and sent on to a drive processor, which adds harmonics to the signal. The drive processor’s output serially feeds a compressor with attack, release, sustain and output-level controls; the sustain control simultaneously lowers the compressor’s threshold, increases the ratio and applies makeup gain. The compressor’s output serially feeds a 2-band parametric equalizer that, like the parametric equalizers that serve individual IRs, can also provide shelving, and highpass and lowpass filtering.

In the bottom-right corner of the GUI, separate faders control the plug-in’s output levels for dry and wet signals; these signals can be independently muted and panned in the stereo field. A preference setting locks the dry and wet levels and mute settings when you load presets; that’s particularly useful when feeding REmatrix via sends for tracks, in which setup you’d always want to audition 100-percent wet signal.

The GUI is fast and easy to navigate after you spend about an hour learning it. Online documentation and a contextual-help function bring you up to speed with REmatrix’s finer points of operation.

Give Me Space

REmatrix offers a large variety of IRs, many of which sound great. The only IRs I was consistently unimpressed with were those for the Special slot; they comprise many highly effected reverbs, some resonating at distinct pitches and others creating strong echo patterns or bubbly or flanging sounds.

The only bug I encountered was that mute buttons sometimes stayed lit after unmuting a slot (Overloud is correcting this in a future update). I liked that I could temporarily bypass all Master effects and they would remain bypassed while I auditioned each IR in turn—a good starting point for rolling my own presets..

On a rock mix, I sent the snare drum to REmatrix and recalled a short, dark, quasi-gated plate IR, to which I gave the maximum stereo spread. I added an IR for a small room, giving it a narrower spread and severely boosting shelving EQ above 2.44 kHz in the room’s Extended Controls panel. The room’s reverb time was a half-second longer than the plate’s. The combined effect was a bright ’verb with ostensible heavy low-frequency damping—the plate’s dark tail was first to die off—starting out wide and then collapsing on itself. To this mix, I added a medium-length, highly diffuse algorithmic reverb for added density. Switching in the compressor—with high sustain setting—made the reverb explode. Adding moderate drive processing to the mix created just enough distortion to push the sound over the top. The resulting sound was phenomenal.

Because REmatrix doesn’t provide damping controls, I found it a little difficult to perfectly meld a hall IR’s reverb tail with a lead vocal on a haunting ballad. And as REmatrix couldn’t sync the hall’s predelay time to my DAW’s tempo, I had to calculate and set a 32nd-note predelay manually. That accomplished, I was well on my way to creating a beautiful effect. I added tightly spaced, lowpass-filtered early reflections and mild chorusing for a rich stereo ADT effect. At the end of the effects chain, I dialed in a quiet, regenerated stereo delay, attenuating the echoes’ extreme highs and lows. The end result was a big vocal sprinkled with a shadowy, rolling reverb that sounded wonderfully ghostly.

The Big Picture

REmatrix is a great tool for building super-thick, multi-layered reverbs and complex ambience effects. It doesn’t replace a full-featured algorithmic reverb; the ability to artificially edit room size, ER spacing, diffusion and other parameters makes an algorithmic ’verb more adaptable than an IR. But REmatrix does way more than generate a single reverb. It produces outstanding, composite effects my algorithmic reverbs—and other convolution reverbs, for that matter—cannot. It’s a unique product in a me-too market. I like that!

Try This

To make a vocal track sound bigger without washing it in reverb, add a little Early IR to the wet mix. If the effect sounds too ambient, narrow the IR’s stereo spread in its Extended Controls panel to 0% or lower setting. Adding some Drive effect—with 30% to 40% drive setting—will make the vocal sound bigger still.